Feed control for concrete pipe machine

ABSTRACT

A PACKER HEAD CONCRETE PIPE MACHINE FOR MAKING A CYLINDRICAL CONCRETE PIPE IN AN UPRIGHT MOLD. CONCRETE IS MOVED FROM A HOPPER HY A CONVEYOR INTO AN UPRIGHT MOLD ON TOP OF A ROTATABLE PACKER HEAD. A POWER DRIVEN CARRIAGE OPERATES TO MOVE THE ROTATABLE PACKER HEAD UPWARDLY TO CONTINUOUSLY MOVE AND PACK THE CONCRETE OUTWARDLY AGAINST THE CYLINDRICAL MOLD TO FORM THE CYLINDRICAL PIPE. A CONTROL MEANS, OPERABLE TO SENSE THE AMOUNT OF CONCRETE ON THE PACKER HEAD, CONTROLS THE CONVEYOR SPEED, OR STARTS AND STOPS IT, SO THAT A SUBSTANTIALLY CONSTANT SUPPLY OF CONCRETE IS AVAILABLE OVER THE PACKER HEAD.

NOV. 16, 1971 0555 3,619,872

FEED CONTROL FOR CONCRETE PIPE MACHINE Filed July 22, 1969 3 Sheets-Sheet 1 lNVIiN'l ()R. A/AVHREO 7. F0556 di iiffw NOV. 16, 1971 1' FQSSE FEED CONTROL FOR CONCRETE PIPE MACHINE Filed July 22, 1969 3 Sheets-Sheet 2 FIG: 7 BY MMArM NOV. 16, 1971 I 0555 3,619,872

FEED CONTROL FOR CONCRETE PIPE MACHINE Filed July 22, 1969 3 Sheets-Sheet 3 FIE. 5'

MOTOR COl/fIQOL UNIT /3 32 lNVI-JN'lu/e FIE. 5' A64 M41220 7- F0555 United States Patent O 3,619,872 FEED CONTROL FOR CONCRETE PIPE MACHINE Navarro T. Fosse, Nashua, Iowa, assignor to Hydrotile Machinery Company, Nashua, Iowa Filed July 22, 1969, Ser. No. 843,588 Int. Cl. B28b 21/26 U.S. Cl. 25-36 25 Claims ABSTRACT OF THE DISCLOSURE A packer head concrete pipe machine for making a cylindrical concrete pipe in an upright mold. Concrete is moved from a hopper by a conveyor into an upright mold on top of a rotatable packer head. A power driven carriage operates to move the rotatable packer head upwardly to continuously move and pack the concrete outwardly against the cylindrical mold to form the cylindrical pipe. A control means, operable to sense the amount of concrete on the packer head, controls the conveyor speed, or starts and stops it, so that a substantially constant supply of concrete is available over the packer head.

BACKGROUND OF INVENTION Packer head concrete pipe making machines, as shown in U.S. Pat. No. 3,262,175, have a combined vertically moving and rotating packer head operable to form a cylindrical wall in a pipe forming mold. In the casting of a concrete pipe, the packer head is initially positioned at the bottom of the mold and the concrete is continuously poured into the mold on top of the packer head. The concrete is continuously supplied into the mold as the packer head moves upwardly and rotates to force the concrete outwardly to form the tubular concrete pipe. Sometimes there is an overfeed which is corrected by a temporary interruption in the feeding of the concrete into the pipe. There must always be a supply of concrete above the packer head in order to continuously form a homogeneous cylindrical concrete wall. An excess amount of concrete interferes with the operation of the packer head and is moved up onto the top table when the packer head emerges from the top of the mold. The excess concrete is collected in a concrete feeding device and moved back into the next mold.

SUMMARY OF INVENTION The invention relates to a packer head concrete pipe making machine having control means for regulating the feeding of concrete into the mold to provide a substantially constant supply of concrete to the packer head. The control means functions in conjunction with the concrete feeding conveyor to regulate the amount of concrete moved into the mold. The control means is operable to regulate the speed of the conveyor, or starts and stops it, in response to the level of the concrete above the packer head.

An object of the invention is to provide a concrete pipe making machine with a concrete supply control apparatus which automatically maintains a continuous supply of concrete adjacent the packer head operating in a mold. A further object of the invention is to provide a concrete feeding control system which automatically terminates the supply of concrete to the mold upon completion of the concrete pipe so that a minimum of excess concrete remains after the pipe is completed. Another object of the invention is to provide a concrete supply control which can be adjusted to vary the amount of concrete available to the packer head.

In the drawings:

FIG. 1 is a front elevational view of a concrete pipe making machine equipped with the concrete feeder control system of the invention;

3,619,872 Patented Nov. 16, 1971 FIG. 2 is an enlarged fragmentary sectional view taken along the line 22 of FIG. 1;

FIG. 3 is an enlarged sectional view of the sensing probe of the concrete feeder control system;

FIG. 4 is an enlarged sectional view taken along the line 4--4 of FIG. 3;

FIG. 5 is a diagrammatic view of the feeder control system of the invention;

FIG. 6 is a diagrammatic view of a modification of the feeder control system of the invention; and

FIG. 7 is a diagrammatic view of a further modification of the feeder control system of the invention.

Referring to the drawings, there is shown in FIG. 1 a packer head concrete pipe making machine, indicated generally at 10, having an upright frame 11 mounted on a base 12. Frame 11 is located over an upright cylindrical pipe mold 13 used in the formation of a concrete pipe. Located over the mold 13 is a horizontal feeder table 14. Opposite portions of the feeder table 14 are slidably mounted on upright guide rods 16 secured to and extended downwardly from a transverse cross frame 17. The feeder table 14 is operable to be raised and lowered to accommodate different sized molds. Hydraulic cylinders, screws, or winches (not shown) can be used to elevate and lower the feeder table 14. Located on the feeder table 14 is a concrete feeding device 18 operable to direct the concrete discharge from a conveyor 19 into the mold and store surplus concrete left over in the formation of a pipe for deposit into a subsequent mold. A detailed disclosure of the concrete feeding device 18 is shown and described in copending U.S. application Ser. No. 709,624. As shown in FIG. 2, the conveyor 19 picks up concrete from a hopper 21 and discharges the concrete 22 into the mold 13 through the concrete feeding device 18.

Returning to FIG. 1, positioned above the cross frame 17 is a power driven movable carriage 23 slidably mounted on upright guide rods 24. Opposite ends of the carriage 23 are associated with elevating means, as hydraulic cylinders, screws, or winches, (not shown) operable to raise and lower the carriage 23 along the upright frame 11. Extended downwardly from the center of carriage 23 is a non-rotatable tube 26 enclosing a rotatable shaft 27. Rollers 25, on cross frame 17, guide the tube 26 along a vertical path. As shown in FIG. 2, the lower end of shaft 27 is connected to a rotary packer head, indicated generally at 28. A motor 29, mounted on the carriage 23, drives a power transmission unit 31 operably connected to the shaft 27 so that the packer head 28 simultaneously rotates and moves in a vertical direction continuously forming a concrete wall in the mold 13.

Packer head 28 has a generally cylindrical shape. Secured to the top portion of the packer head are upwardly directed blades 32 which carry the concrete 22 circumferentially and radially, as indicated by the arrows 33, outwardly toward the walls of the mold 13. A series of circumferentially spaced rollers 34 are located below the blades 32 to pack the concrete against the mold 13. The bottom portion of the packer head has a smooth cylindrical wall 36 operable to work and finish the concrete to form the cylindrical concrete pipe 37.

It is essential, in the continuous formation of the pipe 37, that there be a substantially even supply of concrete 22 on the packer head 28. This concrete is fed by the blades 32 outwardly against the mold wall 13. If there is an insufficient amount of concrete, the pipe wall will vary in thickness or will be improperly packed, be of poor quality and/ or possibly have voids. An excess amount of concrete above the packer head 28 interferes with the effective operation of the blades 32 and also appreciably increases the load on the drive system and decreases uniformity of the pipe produced.

As shown in FIG. 2, the level of the concrete 22 in the mold above the packer head 28 is maintained by a control system, indicated generally at 38. The control system senses the level of the concrete 22 in the mold above the packer head 28 to operate the conveyor 19 and thereby control the amount of concrete supplied to the mold.

The conveyor 19 comprises an endless belt 39 located under the hopper 21 to move a continuous supply of concrete 22 from the hopper into the mold. The belt is trained about an end drum or roller 41 and is driven by a motor 42. A belt drive 43 drivably connects the motor 42 with the drum 41. Drive 43 can be an endless chain or a direct shaft coupling to motor 42.

The concrete feeder control system 38 has a sensing probe, indicated generally at 44, located within the mold adjacent the top of the packer head 28. A bracket 46 adjustably secures the probe 44 to the stationary upright tube 26. The probe 44 is electrically coupled through a line 47 to limit switch 48 operable to disconnect the power to the conveyor motor 42 to terminate the depositing of concrete into the mold upon completion of the pipe. As shown in FIG. 1, limit switch 48 is secured to the upper portion of frame 11 and is engaged by an ear 48A attached to a portion of the carriage 23 guided on the upright rods 24. The limit switch, which is normally closed, is electrically coupled to a control unit 49 operable to control the speed of the motor 42. The control unit 49 has an adjustable time delay circuit so that the conveyor motor will stop only after the probe has made contact for a period of time between to 2 seconds. This prevents continuous start-stop operation of the conveyor motor. The time delay circuit also delays the turning of the motor off after the probe contact with the concrete has been broken. A line 51 connects the control relay 49 to the motor 42. As shown in FIG. 3, the probe 44 has a linear upright portion 52 located in the recess in the back of the bracket 46. A plate 53 secures the portion 42 to the bracket. The upper end of the probe 44 has a coupling 54 for receiving a connector attached to line 47 to electrically couple the line 47 with an electrical conductor or electrode '56 of the probe. The electrode 56 is an elongated metal rod which is covered with tubular electrical insulating material 57. The lower end of the probe is bent in an outward direction so that the exposed lower end 56A of the electrode is spaced from the tube 26. The lower end 58 extends outwardly at an angle for about to 20 degrees with respect to the vertical.

The entire probe 44 may be vertically adjusted along the tube 26. A clamp bolt 59 is used to releasably clamp opposite arcuate portions of the bracket 46 about the tube 26. In this manner, the relative vertical position of the electrode end 56A may be varied relative to the top of the packer head 28 thereby regulating the level of the concrete on the packer head.

In use, when the electrode end 56A comes in contact with the concrete 22, an electrical circuit to the control unit 49 is closed and reduces or terminates the power supply to slow or stop the conveyor motor 42 after a short period of time determined by the time delay circuit in the control unit 49. As the concrete on the packer head 28 is moved outwardly and packed against the wall of the mold 13, the electrode end 56A disengages the concrete and opens the circuit to the control unit 49. At this time, the power is supplied to the motor 42 so that additional concrete is deposited into the mold 13. When the packer head has reached the top of the mold, the limit switch 48 is tripped to close a circuit to the control unit 49 to terminate the power to the motor 42.

Referring to FIG. 5, there is shown a modification of the motor speed control for the conveyor 19. The conveyor belt 39 is driven by a hydraulic motor 42A supplied with a source of hydraulic fluid under pressure from a pump 62. The motor discharges the hydraulic fluid into a rservoir 63 connected to the inlet of pump 62. The pump 62 discharges hydraulic fluid under pressure to a pair of valves 64 and 66. The valves 64 and 66 are solenoicl operated valves connected to the control unit 49A. A line 47 connects the unit 49A to the limit switch 48 and the probe 44. The control unit 49A is operable to operate the valve 64 when the probe circuit 44 is closed and operate the valve 66 when the probe circuit is open. The valve 64 is connected to a throttle valve 67 adjustable to regulate the flow of hydraulic fluid to the motor 42A. In a similar manner, valve 66 is connected to the throttle valve 68 connected to motor 42A. The throttle valves 67 and 68 are adjustable whereby the speed of the motor 42A may be regulated. For example, when the valve 64 is open, the throttle valve 67 may be adjusted to run the motor 42A at a relatively slow rate of speed or even stop the motor. Alternatively, when the valve 66 is open, the throttle valve 68 may be adjusted to run the motor 42A at a high rate of speed or at a rate of speed which will continuously supply the mold 13 with suflicient concrete to maintain the proper level of concrete above the packer head 28. When the limit switch 48 opens, both valves 66 and 67 close and the feed conveyor stops. The valves 64 and 66 can be arranged so that they are both open for high speed operation of the motor. When one valve is closed, the motor runs at a slow speed.

Referring to FIG. 6, there is shown a concrete feeder control system having a pneumatic sensing probe, indicated generally at 69, attached to the packer head tube 26 with brackets 71 and located in the mold 13. The probe 69 comprises an elongated upright tubular member 72 attached at its upper end to a source of pneumatic fluid 73, as air, under pressure. The lower end of tubular member 72 has an enlarged chamber 74 enclosing a valve 75. Projected downwardly from valve 75 is a stem 76. The stem 76 extends through the vent hole 77 in the bottom of chamber 74 which is normally closed with the valve 75. The probe 69 includes an ele-ctro-pneumatic transducer, indicated generally at 78, for transmitting an electrical signal to the motor control relay 493. The transducer 78 is a pneumatically operated electrical switch having expandable and contractible bellows 79 connected to a movable member adaptable to engage electrical contacts 82 and 83. A pneumatic line 84- connects the bellows 79 with the tubular member 72. Located upstream of line 84 is a restriction 86 to limit the rate of flow of pneumatic fluid into the lower portion of tubular member 72 and bellows 79. The restriction 86 functions to provide smooth operation of the concrete feeder control system.

The conveyor motor 42B is a hydraulic motor supplied with hydraulic fluid under pressure from a pump 87. The pump 87 is connected to a reservoir 88, a first valve 89 and a second valve 91. The motor control unit 49B functions to operate the valves 89 and 91 in response to the opening and the closing of the switch 81. When the switch 81 is closed, the valve 89 is operable to permit the flow of hydraulic fluid to the motor 42B to operate the motor at its normal rate of speed. When the switch 81 is open, the valve 91 is actuated to supply the motor 423 with less hydraulic fluid so that the motor Will operate at a slower rate of speed reducing the amount of concrete dispensed into the mold 13. In this manner, the level of the concrete above the packer head 28 is maintained at a substantially even level.

In use, the air 73 enters through the supply line and passes through the restrictor 86 to load the bellows 79 closing switch 81 and holding the valve 75 in the closed position. Interrupted and intermittent actuation of the valve 75 will not reduce the pressure in the tubular member 72 to a suflicient amount to open the switch 81. When the level of the concrete 22 above the packer head 28 is suflicient to actuate the valve 75 by continuously engaging the stem 76, the air in tubular member 72 and the bellows 79 will escape to the atmosphere. On reduction of the pressure of the air in the bellows 79, the switch 81 will move from the contacts 82 and 83. This will activate the slow valve 91 thereby reducing the speed of the hydraulic conveyor motor 42B. The valve 91 may be adjusted such that the motor 42B will be shut off so that no additional concrete is supplied to the mold. When the level of concrete is lowered to a point such that the valve 75 returns to the closed position, the pressure in the bellows will increase closing the switch 81. This activates the motor control relay 493 to a condition to operate the normal running valve 89 to supply the motor 42B with hydraulic fluid under pressure.

Referring to FIG. 7, there is shown a concrete feeder control system having signal level control, indicated generally at 92. The control 92 includes an ultrasonic transducer 93 connected to a cable 94 located adjacent the packer head tube 26 above the packer head 28. A bracket 96 adjustably secures the cable, as well as the transducer 93, to the tube 26. The cable electrically connects the transducer 93 with an electronic unit 97 which serves as a motor control unit for the motor 42 operable to drive the conveyor 19 to discharge concrete 22 into the mold 13. The transducer 93 is located above the level of the concrete 22 over the packer head 28 and is operable to sense the level of the concrete in the mold 13. The transducer projects ultrasonic signals, indicated as arrows 98, and receives an echo from the top of the concrete 22. This signal is directed to the outer peripheral portion of the concrete so that the transducer is actually sensing the amount of concrete that is immediately available to be worked into a cylindrical shape or form against the mold 13. The electronic unit 97 includes a timing circuit that measures the time it takes the signal to travel from the transducer 93 and back. This time is converted into voltage used to vary the speed of the motor '42. As the packer head 28 reaches the top of the mold, the limit switch 48 is actuated to signal the electronic unit 97 to terminate or stop the motor 42, thus terminating the supply of concrete discharged into the mold 13.

The signal level control 92 can be a radar sender and receiver unit mounted on either the packer head tube 26 or the carriage 23 if the machine does not have a shaft housing or tube. This unit is used in conjunction with a time delay and electronic control circuits to control the operation, starting and stopping of the conveyor motor.

While there have been shown and described preferred embodiments of a concrete feeder control system operable to maintain a substantially constant level of concrete above the pipe forming packer head located in a concrete mold, it is to be understood that various changes in the machine and feeder control system may be made by those skilled in the art without departing from the spirit of the invention.

The feed control systems described and shown in the drawing can be used with machines operable to make drain tile, well curbing, concrete sleeves and any other cylindrical products. The sizes of these machines can vary to produce relatively small diameter pipes or tile to large diameter structures.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A concrete pipe making machine comprising: an upright mold, a packer head rotatably located in the mold, means to rotate and axially move the packer head relative to the mold, means for feeding concrete into the mold whereby the rotating and axially moving packer head forms a concrete pipe, and control means operating the means for feeding concrete into the mold, in response to the level of concrete above the packer head, to provide a supply of concrete for the packer head, said control means including concrete level sensing means axially movable with said packer head for sensing the level of concrete above the packer head whereby the control means operates the means for feeding concrete into the mold in a manner to maintain a substantially constant amount of concrete above the packer head.

2. The machine of claim =1 wherein: the means for feeding concrete into the mold includes a conveyor and motor means operating the conveyor, said control means operable to regulate the speed of said motor means.

3. A concrete pipe making machine comprising: an upright mold, a packer head rotatably located in the mold, means to rotate and axially move the packer head relative to the mold, means for feeding concrete into the mold whereby the rotating and axially movable packer head forms a concrete pipe, said means including a conveyor and motor means operating the conveyor, and control means operable to regulate the speed of said motor means, said control means includes a concrete level sensing unit connected to a portion of the means to rotate and axially move the packer head so that the sensing unit axially moves with the packer head, and motor speed control apparatus controlled by the sensing unit operable to vary the speed of the motor means to maintain a supply of concrete over the packer head.

4. The machine of claim 3 wherein: the sensing unit includes an electrical sensing circuit having a probe adapted to contact the concrete above the packer head to complete the circuit thereby controlling the means for feeding concrete into the mold.

5. The machine of claim 4 wherein: said probe has an outwardly directed lower portion partially covered with electrical insulating material.

6. The machine of claim 4 including: an upright member for supporting the packer head and means for mounting the probe on the upright member.

7. The machine of claim 4 wherein: said electrical sensing circuit includes a time delay circuit operable to control the means for feeding concrete into the mold after the probe has engaged the concrete over a period of time.

8. The machine of claim 4 including: means in said circuit operable to terminate movement of the concrete into the mold as the packer head approaches the top of the mold.

9. The machine of claim 1 wherein: the means for feeding concrete into the mold includes a conveyor and a hydraulic fluid motor for operating the conveyor, said control means including valve means operable to regulate the supply of hydraulic fluid for the motor thereby varying the speed of the motor and the speed of the conveyor driven by the motor, a control unit for operating the valves, said concrete level sensing means is operable to signal the control unit to operate the valves in response to the level of concrete above the packer head.

10. The machine of claim 9 wherein: the sensing unit means is a probe having an electrode adapted to engage the top of the concrete in the mold above the packer head.

11. The machine of claim 9 wherein: the sensing unit means is a member having an air chamber, valve means operable to vent said chamber, in response to the level of concrete in the mold, and an electro-pneumatic transducer operable to signal the control unit in response to the air pressure in said chamber whereby the control unit operates said valves to vary the speed of the motor.

12. The machine of claim 1 wherein: the sensing means includes a transducer located above the packer head to sense the level of concrete above the packer head with ultrasonic signals and electronic circuit means responsive to said signals for controlling the operation of the means for feeding concrete into the mold.

13. The machine of claim 1 wherein: the sensing means includes a radar unit located above the packer head to sense the level of concrete in the mold above the packer head with electronic signals, and electronic circuit means responsive to said signals for controlling the operation of the means for feeding concrete into the mold.

14. A concrete pipe making machine comprising: an upright mold, a packer head rotatably located in the 7 mold, means to support, rotate and axially move the packer head relative to the mold, means for feeding concrete into the mold whereby the rotating and axially moving packer head forms a concrete pipe, and control means including an electrical sensing circuit having a probe adapted to contact the concrete above the packer head to complete the circuit, said circuit operable to control the means for feeding concrete into the mold in response to the level of concrete above the packer head to maintain an amount of concrete above the packer head, and means mounting the probe on the means for supporting the packer head whereby the probe axially moves with the packer head.

15. The machine of claim 14 wherein: said probe has an outwardly directed lower portion adapted to contact the concrete above the packer head.

16. The machine of claim 14 wherein: said electrical sensing circuit includes a time delay circuit operable to control the means for feeding concrete into the mold after the probe has engaged the concrete over a. period of time.

17. The machine of claim 14 including: means in said circuit operable to terminate movement of the concrete into the mold as the packer head approaches the top of the mold.

18. The machine of claim 14 wherein: the means for feeding concrete into the mold includes a conveyor and a hydraulic fluid motor for operating the conveyor, said control means including valve means operable to regulate the supply of hydraulic fluid for the motor thereby varying the speed of the motor and the speed of the conveyor driven by the motor, a control unit for operating the valves, said circuit operable to signal the control unit to operate the valves in response to the level of concrete above the packer head.

19. The machine of claim 14 wherein: the means for feeding concrete into the mold includes a conveyor and motor means operating the conveyor, said control means operable to regulate the speed of said motor means.

20. The machine of claim 19 wherein: the motor means is a hydraulic fluid motor for operating the conveyor, said control means including valve means operable to regulate a supply of hydraulic fluid for the motor thereby varying the speed of the motor and the speed of the conveyor driven by the motor, a control unit for operating the valves, said sensing circuit operable to sig- 11211 the control unit to operate the valves in response to the level of concrete above the packer head.

21. The machine of claim 3 wherein: the motor means is a hydraulic fluid motor drivably coupled to the conveyor, said control means including valve means operable to regulate the supply of hydraulic fluid to the motor thereby varying the speed of the motor.

22. The machine of claim 1 wherein: the sensing means includes an electrical sensing circuit having a probe adapted to contact the concrete above the packer head to complete the circuit thereby controlling the means for feeding concrete into the mold.

23. The machine of claim 22 wherein: said probe has an outwardly directed lower portion adapted to contact the concrete in the mold above the packer head.

24. The machine of claim 22 wherein: said electrical sensing circuit includes a time delay circuit operable to control the means for feeding concrete into the mold after the probe has engaged the concrete over a period of time.

25. The machine of claim 22 including: means in said circuit operable to terminate movement of the concrete into the mold as the packer head approaches the top of the mold.

References Cited UNITED STATES PATENTS 1,904,094 4/1933 Snyder 2536 X 2,583,842 1/1952 'Hendrickson l41192 X 2,593,665 4/1952 Glassen 2536 X 2,660,769 12/1953 Bennett 164156 3,019,764 2/ 1962 Schilling ZZZ-64 X 3,262,175 7/1966 Gourlie 25-36 3,378,061 4/1968 Von Alt et al. l64-156 3,453,706 7/1969 Chanlund 25-36 FOREIGN PATENTS 775,919 5/1957 Great Britain 2536 I. SPENCER OVERHOLS'ER, Primary Examiner B. D. TOBOR, Assistant Examiner 

